Low cost-high resolution radar for commercial and industrial applications

Abstract

A low-cost, high-resolution radar based detection system has a pulse repetition frequency generator connected to first and second narrow pulse modulators. A transmit channel is connected to the first narrow pulse modulator and emits pulse modulated carrier based transmit signals having a prescribed carrier frequency and a prescribed duration. A receive channel is connected to the second narrow pulse modulator. A time delay circuit delays the output of the second pulse modulator to the receive channel and a mixer mixes a portion of one of the pulse modulated carrier based transmit signals reflected from an object with the output of the second narrow pulse modulator.

What is claimed is: 
     
       1. A radar based detection system, comprising: a pulse repetition frequency generator connected to first and second narrow pulse modulators;   a transmit channel connected to said first narrow pulse modulator, said transmit channel emitting pulse modulated carrier based transmit signals having a prescribed carrier frequency and said signals having a prescribed duration;   a receive channel connected to said second narrow pulse modulator;   a time delay circuit for delaying output of said second pulse modulator to said receive channel; and   a mixer for mixing a portion of one of the pulse modulated carrier based transmit signals reflected from an object with the output of said second narrow pulse modulator.   
     
     
       2. A radar based detection system as recited in claim 1 wherein said first narrow pulse modulator transmits multiple pulses at a predetermined interval; said second narrow pulse modulator transmits multiple pulses at a predetermined interval; and said mixer output is a series of phase relations. 
     
     
       3. A radar based detection system as recited in claim 1, wherein said prescribed carrier frequency is on the order of 5.8 GHz. 
     
     
       4. A radar based detection system as recited in claim 1, wherein said pulse modulated carrier based transmit signals have a center frequency in the millimeter waveband. 
     
     
       5. A radar based detection system as recited in claim 1, wherein said pulse modulated carrier based transmit signals have a center frequency in the microwave band. 
     
     
       6. A radar based detection system as recited in claim 1, wherein said carrier based transmit signals have a bandwidth on the order of 3 GHz. 
     
     
       7. A radar based detection system as recited in claim 1 wherein said transmit channel is connected to a directional antenna. 
     
     
       8. A radar based detection system, comprising: a pulse repetition frequency generator connected to first and second narrow pulse modulators;   a transmit channel connected to said first narrow pulse modulator, said transmit channel emitting pulse modulated carrier based transmit signals having a prescribed carrier frequency and said signals having a prescribed duration;   a receive channel connected to said second narrow pulse modulator;   a time delay circuit for delaying output of said second pulse modulator to said receive channel; and   a quadrature power splitter connected to a receive antenna, said quadrature power splitter splitting a received pulse reflected from an object into a quadrature channel and an in-phase channel for the detection of the object.   
     
     
       9. A radar based detection system as recited in claim 8, wherein said prescribed carrier frequency is on the order of 5.8 GHz. 
     
     
       10. A radar based detection system as recited in claim 8, wherein said time delay circuit has a predetermined time interval that is variable for scanning ranges. 
     
     
       11. A radar based detection system as recited in claim 8, wherein said object is stationary. 
     
     
       12. A radar based detection system as recited in claim 8, wherein said object is moving.